From: Gary Wright <gwtmp01@...>
Date: 2010-02-06T03:57:12+09:00
Subject: Re: function lookup in ruby


On Feb 5, 2010, at 1:42 PM, Cnm Cnm wrote:

> Hi all,
> I was wondering what happened in the background of following snippet.
> First I define a method v1, and I am able to call v1. Then I redefine v1
> as an array; after that I can only call v1 as a function by calling
> v1(). How does ruby look up v1 as a function and variable? Thanks
> 
> irb(main):001:0> def v1
> irb(main):002:1> puts 'printing from method v1'
> irb(main):003:1> end
> => nil
> irb(main):004:0> v1
> printing from method v1

At this point the only thing named 'v1' is a method
so the method is called.

> => nil
> irb(main):005:0> v1 = []
> => []

Now there are two things named 'v1' a method
and a local variable. Name resolution prefers
local variables so...

> irb(main):006:0> v1
> => []

The local variable is referenced

> irb(main):007:0> v1()
> printing from method v1
> => nil

By adding the explicit parens you've given Ruby
a hint that you want to call a method and not
lookup a local variable.

Alternatively you could do:

	self.v1

which would also reference the method and not
the local variable.

Gary Wright